Academic Journals & Conferences - high-speed friction strengtheninghttp://science.lp.edu.ua/uk/index-terms/high-speed-friction-strengthening
ukRESEARCH OF INFLUENCE OF OSCILLATIONS OF TOOL-PART SYSTEM ON ROUGHNESS OF SURFACE LAYER DURING HIGH-SPEED FRICTION STRENGTHENINGhttp://science.lp.edu.ua/uk/node/3709
<div class="field field-name-field-authors field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Petro Dmyterko, Yurii Novitskyi, Volodymyr Gurey</div></div></div><div class="field field-name-field-abstract field-type-text-long field-label-inline clearfix"><div class="field-label">Анотація:&nbsp;</div><div class="field-items"><div class="field-item even">During the discontinued friction strengthening except of the high-speed friction the
processes of high-frequency shock loadings appears in the tool-part contact zone. The vibrations
occur in the machine elastic system. During the vibrations of elastic systems, in the material of
elastic elements and in the connecting units of the structure parts the energy dissipation into the
ambient medium takes place. The energy dissipation of vibrations occurs due to the influence of the
inelastic resistance forces on which the energy of the oscillatory system is spent. The vibrations of
the tool-part system during the friction strengthening are similar to forced oscillations. However, for
some particles of the part these oscillations are damped ones because the tool moves along the
surface. The vibrations of the elastic system of the machine during the discontinued friction
strengthening in the first approximation may be considered as free oscillations. For their
investigation let us use the method of shock (impact) perturbation with a help of special measuring
hammer which allows defining of the damping coefficient. With a help of the accelerometer and the
hammer the shock (impact) curve and the registration curve of the tool-part vibrations were
obtained. The obtained registration curve of tool-part vibrations was expanded into the Fourier series
and with a help of MatLab program the obtained signal was filtered. Due to determination of the
amplitude of vibrations and the oscillation period the logarithmic decrement of damping was
defined. This parameter may be used for determination of the dynamic parameters of the oscillatory
system of the converted machine.
For defining the oscillations which arises in the part being machined we used the
dynamometer, in which the piezo-crystal sensor was rigidly fixed. This sensor allows the readout of
oscillations along three directions (along vertical, horizontal and transversal axis).
Experimental research showed that the amplitude increased with increasing the number of
processing modes and the oscillation character has exact wave-like form. The working process along
the longitudinal direction has step-wise character. The single contact zone is heated to high
temperatures; the metal softens; the friction coefficient decreases and the step-wise transportation of
the part along the longitudal direction is being carried out. These phenomena are also confirmed by
the figure of the machined surface and by the results of investigation of the topography of the
machined surface. It is also experimentally determined that horizontal and vertical displacements of
the spindle and the table vibrate with the frequencies close to resonance ones. With increasing of the
tool rotation speed these vibrations have the character of damped ones and this phenomenon allows
reducing the parameters of roughness, undulation and flatness of the surfaces being strengthened.</div></div></div><div class="field field-name-field-index-terms field-type-taxonomy-term-reference field-label-inline clearfix"><h3 class="field-label">Ключові слова: </h3><ul class="links inline"><li class="taxonomy-term-reference-0"><a href="/uk/index-terms/oscillations" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">oscillations</a></li><li class="taxonomy-term-reference-1"><a href="/uk/index-terms/tool-part-system" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">tool-part system</a></li><li class="taxonomy-term-reference-2"><a href="/uk/index-terms/roughness" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">roughness</a></li><li class="taxonomy-term-reference-3"><a href="/uk/index-terms/surface-layer" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">surface layer</a></li><li class="taxonomy-term-reference-4"><a href="/uk/index-terms/high-speed-friction-strengthening" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">high-speed friction strengthening</a></li></ul></div><div class="field field-name-field-full-text-file field-type-file field-label-hidden"><div class="field-items"><div class="field-item even"><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="http://science.lp.edu.ua/sites/default/files/Papers/5_47-54.pdf" type="application/pdf; length=671017">5_47-54.pdf</a></span></div></div></div><div class="field field-name-field-received field-type-datetime field-label-above"><div class="field-label">Received:&nbsp;</div><div class="field-items"><div class="field-item even"><span class="date-display-single" property="dc:date" datatype="xsd:dateTime" content="2016-03-30T00:00:00+03:00">Wednesday, March 30, 2016</span></div></div></div><div class="field field-name-field-accepted field-type-datetime field-label-above"><div class="field-label">Accepted:&nbsp;</div><div class="field-items"><div class="field-item even"><span class="date-display-single" property="dc:date" datatype="xsd:dateTime" content="2016-08-24T00:00:00+03:00">Wednesday, August 24, 2016</span></div></div></div>Tue, 24 Jan 2017 07:07:57 +0000vitaliy_korendiy_32653709 at http://science.lp.edu.uahttp://science.lp.edu.ua/uk/node/3709#comments